Three-wheeled vehicle have long been used for automotive transportation. Their use has been limited because of the problem of instability, for which reason four-wheeled vehicles have become prevalent.
Certain specialized three-wheeled vehicles are used today such as golf carts and delivery and other small utility vehicles, as well as three-wheeled motorcycles used as sport vehicles. To increase stability, these vehicles are generally built with a low center of gravity. This is accomplished by the use of small wheels and the placement of passenger seating in a relatively low position.
In the United States, Federal and local laws place minimums on the diameter of wheels and on the distance of the seat from the ground. This limits the degree of stability possible in the design of three-wheeled vehicles. As a result, many commercially made three-wheeled automobile vehicles manufactured in this country and in others are not legally usable on roads in the U.S. Although many of these are made in and used in Europe, they are not imported into the U.S. Those made here are relegated to "off road" use, or use by governmental agencies such as police, which are permitted to use vehicles which do not conform to these regulations. Three-wheeled motorcycles are generally used by experienced sport motorcycle drivers rather than the average citizen.
Three-wheeled automotive vehicles pose an additional problem owing to their small size relative to the size of the other cars on the roads they share. This is that the driver and passengers do not feel safe or confident unless they are seated relatively high off the road. To be seated low in traffic consisting of conventional cars results in an insecure feeling, deriving most likely from lack of visibility on the part of the driver and the knowledge that he is not conspicuous to other drivers. The achievement of stability in three-wheeled vehicles by the use of low seating and/or small wheels is limited by the regulatory laws mentioned above and by the need for the feeling of height on the part of the passengers and driver.
The need to provide a covering for the passengers as protection against the weather complicates the problem as a structure above the heads of the passengers will tend to elevate the center of gravity by adding weight at a relatively high point.
An additional problem relative to the stability of three-wheeled vehicles is that created by the different situations of balance created in having either one or two passengers aboard, especially if the seating is side by side. The invention addresses itself to this problem as well.
The invention further comprises a series of mechanical features intended generally to lower the center of gravity by reducing the weight of components located at high points on the machine. One of these features is the use of heavy electric storage batteries whose weight is used to adjust the center of gravity and which serve also as the source of energy for the vehicle.
This use of electric storage batteries introduces a further problem, that of providing sufficient energy storage capacity to offer enough range of driving between recharges of the batteries commensurate with practical needs. Numerous electric vehicles exist today. They consist of full sized four-wheeled electric automobiles weighing thousands of pounds, as well as smaller three-wheeled vehicles used as off-road utility vehicles or golf carts. Even these tend to weigh upward of several thousand pounds. There are none used generally on the road for regular transportation due to their general impracticality concerning range, cost, utility, and stability. These problems arise from the need to supply energy storage capacity sufficient to move the weight of the vehicle and its load by means of electric storage batteries which themselves are so heavy as to contribute substantially to the load. They also require heavier chassis construction merely to support them.
It is an object of the invention to provide a unique and improved vehicle which solves the above problems by means of a series of mechanical arrangements which deal simultaneously with the problems of stability, passenger placement, conformity to road statutes as well as problems intrinsic in electric drive, such as energy storage capacity power, and so forth.
A number of three-wheeled vehicles are known such as, for example, disclosed in French Pat. No. 1,011,087, and in U.S. Pat. No. 3,117,648. The vehicles shown in the Landers U.S. Pat. No. 3,117,668 is an electrically powered vehicle having interconnected power and brake controls. This vehicle is provided with a chassis having a driver's compartment portion with speed and braking controls being mounted on the chassis and wheel mounting axle supports are secured to the forward part of the chassis. A frame is pivotably connected to an intermediate part of the chassis and extends along the rear part thereof. A spring system supports the rear part of the chassis on the frame and a power unit mounted on the frame comprises a sealed casing with a differential therein. Wheel mounting axle members project sidewardly from the differential through the casing and are journaled in the frame. An electric motor is carried by the frame and powers one of two counter shafts. A motor control device is mounted on the casing with brake means being connected to the casing and being mounted on the other counter shaft, there being further provided actuating devices for the brake means and a transmission in the casing interconnecting the brake actuating device and the controls whereby the speed of the electric motor is reduced in response to the actuation of the brake.
French Pat. No. 1,142,921 and the Michael U.S. Pat. No. 3,284,130 show windshields with the Michael patent further showing what might be regarded as constituting a canopy. Specifically, the Michael patent discloses a windshield and spray shield construction which comprises an upright windshield frame with devices securing the frame to an upper portion of the front end of the main frame of a motorcycle. The construction also includes devices defining a pair of support arms projecting rearwardly and downwardly from opposite side portions of the lower end portion of the windshield frame. The main frame of the motorcycle includes forwardly and upwardly inclined forward portions from whose upper end the front wheel assembly is pivotably supported. An upstanding flexible spray shield is secured between the aforesaid arms and is passed over the forwardly and upwardly inclined portion of the main frame. The support arms generally parallel the forwardly and upwardly inclined portion of the main frame and are disposed forwardly of the upwardly inclined position.
The prior art fails to reveal a three-wheeled lightweight vehicle with an advantageously positioned center of gravity as is provided in accordance with the invention and as will be discussed in greater detail hereinafter.